Our brain imaging group uses magnetic resonance imaging (MRI) to study
how human brain structure and function adjusts to life conditions. Projects with different
focuses are underway. One of my main interests is time-series tracking of ongoing
maintenance of brain structure. We are using an unconventional N-of-1 MRI design
in which sizes of brain structures are repeatedly measured at regular short intervals
over extended periods in an individual person. The goal is to identify concepts of
brain maintenance that apply at an individual person level that may not be resolvable,
and may be overlooked, by conventional cross-sectional or longitudinal group analysis
designs. Brain structure undergoes recognized major changes at the two ends of the
human lifespan, i.e. during development prenatally and into the initial two decades,
and during the last decade or so, of life. Between early life development and the
last years of aging, mature brain structure must be continuously maintained in a healthy
viable state from week-to-week during normal adulthood.

It is well recognized that a healthy adult brain can undergo structural
plasticity due to learning or injury. In contrast, during periods of baseline normal
living mature brain structure is widely thought to be statically maintained. This
static maintenance view is based on age-related group average rates of structural
change over long periods of years-decades which, when extrapolated to week or other
short intervals, suggest brain structural measures remain static over short intervals.
Interestingly, this view has not been directly tested at an individual person level.

Using an N-of-1 design in which we have reiteratively measured brain structure
at regular intervals over several months in an individual person, we have findings
that support the hypothesis that continuous maintenance of an individual person’s
brain can involve reversing incremental and decremental fluctuations in the structural
thickness of the cerebral cortex that appear to reflect continuous maintenance remodeling/turnover
of cortical substrates. This work suggests that ongoing maintenance of the cortical
structure of an individual person’s brain may not be as static as presently thought.
We are currently pursuing this line of research. In addition, projects that are ongoing
or being developed and led by other imaging group members address further issues including,
e.g., how brain function and structure change over time as a result of a traumatic
experience or traumatic injury.